Range-finding and fire-correction



May 30, 1939- l J. FlEux 2,160,202

RANGE-FINDING AND FIRE-CORRECTION SIGHTTNG DEVICE Filed Dec. 23 1938 3 SheetS'-Sheet l I Il! ,im f

llllf Unvenl'an May 30, 1939.

J. FII-:ux 2,160,202 RANGE-FINDING AND FIRE-CORRECTION SIGHTING DEVICE Filed Dec. 25. 1938 3 Sheets-Sheet 2 7 W/ /f //////////////Ty/ d Hor news J. Pieux 2,150,202 RANGE-FINDING AND FIRE-'CORRECTION SIGHTING DEVICE May 3o, 1939.

Fiied nec. 2s, 1938 3 Sheets-Sheet 5 Unven'or ca/rnman,

Patented May 30, 193.94

.UNITED STATES RANGE-FINDING AND yrma conanc'rrou l sIGrITmG DEVICE Jean Fieux, Paris, France, assignor of one-half to Schneider & Cie, Paris, France, a joint-stock company of France Application December as, 193s, serial No. 247,506 In France October 15, 1937 'somma The present invention relates to a device by means of which it is possible by direct sighting to estimate in a particularly simple and yet suffciently accurate manner from the practical '5 'point of view the distance at which an object forth hereinafter, be adapted and combined withV anyl other suitable additional fire adjusting vdevices, so that the estimation of the distance oi.' the target does not complicate in any way the operations of the gunner, and so that the information obtained in so far as concerns the distance of the target may, without additional operation, be directly and automatically utilised for working out and applying the corrections to be introduced in the aim.

In the first place, the invention substantially comprises disposing in the focal plane of a transparent reector sight of well-known type, in place of the usual cross-wires, an iris diaphragm, the opening of which is adapted/to be varied at will by means of a suitable control device so that 3'5 the image of said opening in the glass of the sight may be caused to circumscribe exactly the apparent contour of the object observed.

In addition, the invention relates to the arrangement and, if desired, the additional calibration of the aforesaid control device, in the iirst place with a view to adapting the latter to each of the different ltargets which it may be necessary to take into consideration (different types of aeroplanes, for example), and secondly,

so that thesaid control device may, as desired,

either simply furnish the indication of the distance to be estimated. in which case the variations in opening of the diaphragm will ,simply play as it were the partfof stadiometer scale, the

same scale being adapted by calibration to each type of target to be considered, or, preferably, introduce, as has been statedabove, directly and automatically the range indication obtained into the auxiliary aim-correction mechanism by means of which the ring is adjusted.

For this latter case, the-invention relates subsidiarily to a control device for varying the opening of the iris, said device comprising an adaptation lever of such a shape that the same angular movement of the correction-control lever (which may be operated directly by the observerlproduces, for each of the different targets which may occur, a variation of opening of the diaphragm, the origin and amplitude of which correspond, as a function of thevdimensions of the target under consideration, to the common zone of ire selected, for example, 200 metres to 600 metres; that is to say, as the operation of the correction control lever, in the case of a targetaeroplane of Wing-spread A, results in a diaphragm opening variation from M to N when the aeroplane passes from the distance 600 metres to the distance 200 metres, the same operation of the said correction control lever will, for the same change of distance 7from 600 metres to200 metres of an aeroplane of wing-spread a, result in a variation in opening of the diaphragm from p to q, p being diiferent from M, and q-p being smaller than' N-M if a is smaller than A or larger if a is larger than A. y

Finally, by way of possible additional combination, the invention relates to such a combination which, as in the case where it is desired to leave the gun xed relatively to the fuselage ofthe aeroplane, permits the adjustment of ring in the known manner by dis ement of the axis of sight, although the means usually employed for this purpose, namely, the movement of the crosswires in their own plane, is no longer ayailable.

The additional combination referred to comprises rendering the objective of the transparent reflector sight movable in its own plane, due to which the parallax of aiming may, by means ofk a suitable control device connecting the objective to the correction mechanism, be corrected and regulated in the same way as in the known case Where it is the cross-wires which are movable.

A particular embodiment of the invention is shown by Way of example in the accompanying drawings and is described hereinafter, but of course this embodiment may be modiiied in its constructional details or may be completed by any useful accessory device Withoutfor that purpose Vdeparting from the scope of the invention.

In these drawings:

Figure 1 shows any elevation of the whole of the device.

Figure 2 shows a section on the line II-II of Figurel.

three plan views with considered, and finally,

(c) In the case of the maximum range of nre considered, it being possible furthermore to select all these ranges arbitrarily and to calibrate the apparatus in consequence.

Figures 6 and 7 show diagrammatically the images seen by the observer in the mirror ofthe sighting device, respectively, the first in the case of an aeroplane of average wing-spread, situated at the shortest range'of re considered, and the l second in the case of the same aeroplane of average wing-spread situated at the maximum range of nre provided, the image seen bythe observer in the same case of an aeroplane of mean wingspread, situated at a range of fire in the vicinity o f' the mean range of nre, being indicated in Figure 1.l

Figures 8 and 9 show two partially sectioned plan views, similar to Figures 3, 4 and 5, for explaining the manner in which the control mechanism employed enables the device to be adapted to various targets (aeroplanes, for example) of'dlfferent dimensions.

As will be seen in these drawings, and more particularly in Figures 1, 2 and 3, the device shown substantially comprises a transparent reflector sight composed, in the usual manner, of a collimator body in two parts I, Ia on which are mounted the usual light condenser 2, the source of light 3 (electric bulb, for example) and the objective 5.

In the present case, however, the transparent reflector sight comprises in addition, disposed in the focal plane of its objective 5, in place -of the usual cross-wires, an iris diaphragm l which, in accordance with the usual art. is formed of a certain number of leaves 6a suitably pivotedin the,

interior' of an annular mounting 8 (secured in the present case to the element Ia of the collimator body) and subjected to the action of a control ring 1.

The driving lug 1a of the latter itself projects through the annular mounting 6, which for this purpose is appropriately slotted at 6b, and engages a recess 8 of a control and adaptatiomlever l which is mounted by means of a circular strap la on the element Ia of the collimator body around which it is consequently adapted to turn, driving with it the control ring 'I and producing, according to its direction of rotation,-the opening or closing of the diaphragm.

likewise fixed on the element I of the collimator body in accordance with the usual art is the clear glass. plate III having parallel faces.-

For reasons which will be indicated hereinafter, the adaptation lever 9 is not controlled directly but is set in movement through the medium of a link II carrying at one end a pin I9 by meansof which it is pivoted to the lever 9, and pivoted at its other end to a pin I1 provided on an operating lever I2 which is pivotally mounted on a support I4.

The lever I2, as is appropriate, comprises at one of its ends an operating handle I2a and at its other end an indicating pointer I2b which moves over a graduated scale I2c marked on the said support Il.

` hinge pin I9 of the then in accordance with The support Il and the element I of the collimator body of the transparent reflector sight are both fixed to a common frame 2l.

For limiting in desired manner the zone of use v of the apparatus stops II and Il areprovidedon the support I4 for preventing the lever I2 from exceeding the extreme positions imposed on it.

Upon simple inspection of Figures l, 3, 4 and 5 on the one part and the supplementary Figures 6 and l on the otherv part, it will be appreciated that, according to the position which it is necessary to give to the lever I2 in order that the latter, through the medium of the link Il and the adaptation lever 3, will impose on the iris diaphragm I an opening such that the image of said opening, seen by the observer at infinity through the transparent glass IIi exactly circumscribes the sighted target (aeroplane, iorl example), the range of the target under consideration will b immediately determined, at least in a sufficiently approximate manner for the usual practice of To render possible the adaptation of the d evice for the observation of a certain number of objects (aeroplanes) of different dimensions, the lever 8 lis provided with a certain number of coupling l holes I3, in each of which it ispossible, as desired,

by its upper end, to

means of the operating knob I9a terminating' insert thelower end ISb of the link II; and in addition, the said lever B is made of such a shape that the same total movement of the operating lever I2 between its v two stops I5, I6, corresponds to different opening startingy points and opening amplitudes ,of the diaphragm, each adapted to each of the different targets (aeroplanes) which are expected to Ipresent themselves.A

It is known in fact that, for the same variation in range, the variation of the angle at which an object is seen is determined according to a simple law which is. a function of the dimensions of the said object.

If. in fact the real diameter of the object is called D and its distance L, its apparent diameter d will be.: l

. L l and consequently the diameter of the opening A to belgiven to the diaphragm will be given by the formula:

A"L l x where lc is a coemcient which is easy to determine as a function of the optical elements of the device.

The shape of the adaptation lever 3 is likewise easy to determine, by ,means of a simple diagram, as a function of the objects which it is desired to take into consideration. 4

Of course, from the point of view of adaptation, the only useful part of said lever is the curved part, that is to say, the part 3b along which are provided the holes Il.

'I'he bent connection 9c which connects the part 9b to the strap 9a is intended to allow for the fact that, practically, the orifice of an iris diaphragm, such as those which are constructed industrially, cannot be reduced to absolute zero.

The use of the adaptation device which has just been described and the result obtained are easy to understand by examining Figures 8 and 9.

If the -smallest of the targets considered occurs, what is indicated in dimensions of the Figure 8, the pin I9 of the link il will be placed in the extreme hole Isa of the adaptation lever 9, and when the lever I 2 passes from the position in which it is shown in solid lines to the position in which it is shown `in chain lines, driving with it the link Il and the adaptation lever 9, it produces a variation in opening of the diaphragm I, the origin of which is in the vicinity of the smallest opening of the said diaphragm, and the amplitude of which is relatively restricted, the said variation corresponding to the law of approach of the target considered.

If, on the contrary, the largest of the targets which has been taken into consideration occurs, then in accordance with what is indicated in Figure 9, the pin v I9 of the link Il is inserted in the hole l8b which is closest to the sight, and at the same time as obtaining a suitable starting point for the opening of the diaphragm, dierent from those which would correspond to the other targets, there will likewise be obtained a much more considerable amplitude of variation of opening of the diaphragm adapted to the law of variation of parallax of the target considered as a function of the range of the latter.

When it is desired to utilise directly the range indication obtained for controlling the corresponding corrections, without even having to trouble about the numerical value of this range indication, the lever I2 is mounted and keyedon the shaft i3 of the automatic correction control mechanism, of which the support Il may, for example, form the casing.

` Under these conditions, the operation of the lever l2 will produce directly the correction corresponding to the range of the target sighted.

Finally, if necessary, a suitable displacement of the objective 5, which displacement may be produced by any adequate mechanism appropriately connecting the said objective to the correction mechanism, permits the firing to be adjusted by deviation of the line of sight, the gun being supposed to be fixed relatively to the fuselage of the aeroplane.

A lateral translation of the objective permits the correction in direction to be effected. Its

translation parallel to the line of sight permits the correction in elevation to be effected.

There is thus provided, altogether, a sighting and correction device which allows for the dis- 'tance of the target in an extremely simple manner without imposing on the user, whoever he may be, either observer or gunner, or observergunner if the two duties are carried out by one person, as is the case in single-seater aeroplanes, any additional eiTort of whatever nature.

The action exerted by the aimer on a single lever, for ensuring that the apparent image of the target will be inscribed exactly in the circle of light seen through the transparent reflector sight is in itself suiiicient to obtain both a correct sight and a correct :tiring correction, allowing for the distance oi the target.

I claim:

l. In a range-finder, the combination of a transparent member through which the target may be observed, means including a lens and an iris diaphragm disposed in the focal plane of said lens for producing an image of the opening of said diaphragm on said transparent member, control means for varying the size of the opening of said diaphragm, relatively movable scale and index-carrying members one of which is fixed relatively to said transparent member, a kinematic linkage connecting the other of said .relatively movable members and said diaphragm control means, and means for varying the transmission ratio of said linkage.

2. In a range-nder, the combination of a transparent member through Whichthe target may be observed, means including a lens and an iris diaphragm disposed in the focal plane of said lens for producing an image of the opening of said diaphragm on said transparent member, control means for varying the size of the opening of said diaphragm, relatively movable scale and index-carrying members, stops for limiting the amplitude of the relative movement of said members, one of said relatively. movable members being fixed -relatively to said transparent member, a kinematic linkage connecting the other of said relatively movable members and said diaphragm control means, and means for simultaneously varying the transmission ratio of said linkage and the position of said diaphragm control means corresponding to the mean relative position of said scale and index-carrying members.

3.. In a range-finder, the combination of a transparent member through which the target may be observed, means including a lens and an iris diaphragm disposed in the focal plane of said lens for producing an image of the 'opening of said diaphragm on said transparent member, means including a control lever for varying the size of the opening of said diaphragm, an operating lever adapted to be manually actuated by the range-iinder operator pivotally mounted .for

movement about an axis parallel to the axis of said lens and diaphragm and xed relatively to said transparent member, a link connecting said operating lever and diaphragm control lever, and means for varying the point of connection between said link and said diaphragm control lever.`

4. In a lire control system for guns, the combination of a transparent member through which the target may be observed, means including a lens vand an iris diaphragm disposed inthe focal plane of said lens for producing an image of the opening of said diaphragm on said transparent member, control means for varying the size of the opening of said diaphragm, means for introducing a range correction into said system, and an operative connection between said last named means and said diaphragm control means whereby the movements of the latter in varying the diaphragm opening are automatically transmitted to said range correction means.

5. In a re control system for guns, the combination of a transparent member through which the target may be observed, means including a lens and an iris diaphragm disposed in the focal plane of said lens for producing an image of the opening of said diaphragm on said transparent member, control means for varying the size of the opening of said diaphragm, means including a member movable between predetermined limits for introducing a range correction into said system, a kinematic linkage connecting said last named member and said diaphragm control means, and means for simultaneously varying the transmission ratio of said linkage and the position of said diaphragm control means corresponding to the mean position of the movable member of said range correction means.

JEAN FIEUX. 

